Dr. Wu's isolation and characterization of the Fap1 molecule, a glycosylated fimbrial structural subunit of Streptococcus parasanguis, was a significant breakthrough in understanding the basic for fimbrial biosynthesis and adhesion in Gram-positive bacteria. Fap1-like molecules and genes involved in Fapl glycosylation are not only highly conserved across oral streptococci but are also present in Streptococcus pneumoniae and in the staophlococci. Dr. Wu's current research on the glycoslylation of Fap1 is extremely exciting. It is likely that a universal glycosylation machinery is present in Gram-positive bacteria and the findings from these studies would be applicable to other organisms. Recently, he identified a gene cluster that is required for the glycosylation of Fap1. He is currently in the process of determining the biosynthetic pathway by which Fap1 is glycosylated using molecular genetic, structural biology, and biochemical approaches. With the support of a K22 award, Dr. Wu will take formal courses in mass spectrometry and bioinformatics and receive hands-on training in Mass spectrometry analysis of the carbohydrate structure and biochemical analysis of key enzymes involved in protein glycosylation. The support of a K22 will provide Dr. Wu with new skills and knowledge in carbohydrate biochemistry that will position him to pursue new avenues in the study of glycosylation of streptococcql adhesions. Dr. Wu is in a unique position to determine the mechanisms of prokaryotic glycosylation and Gram-positive fimbrial biogenesis as the explict genetic tools have been generated in Dr. Fives-Taylor's laboratory over the last 20 years. Dr. Wu's strength in molecular genetics coupled with the training in carbohydrate biochemistry specifically in mass spectrometry analysis and enzymology will enhance his career development in this exciting research area. The results of this proposal will help define the biosynthetic pathway for Fap1 glycosylation. New genes in the pathway may endow microbes with new effector functions or aid in the evasion of host defense, strategies that are important components of disease-causing capabilities of a number of bacterial pathogens. Therefore, elucidation of Fap1 glycosylation may provide a framework for understanding the role of glycoslyation in bacterial pathogenesis.